Brilliant

Level pending

The number of words that can be formed using the letters of the word BRILLIANT such that there is exactly 4 digits between B and T is x.What is x/60


The answer is 168.

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

1 solution

Ashish Menon
May 9, 2016

Let B be the first alphabet and T be the sixth, then there are four words between B and T which can be arranged in 7 ! 2 ! × 2 ! \dfrac{7!}{2! × 2!} ,because I and L repeat and there are 7 alphabets other than B and T. The answer is same even if B is second & T is seventh and B is third and T is eighth & B is fourth and T is ninth & T is first and B is sixth &T is second and B is seventh & T is third and B is eighth & T is fourth and B is ninth.

So, the total number of words that can be formed = 7 ! 2 ! × 2 ! × 8 = 8 ! 2 ! × 2 ! = 10080 \dfrac{7!}{2! × 2!} × 8 = \dfrac{8!}{2! × 2!} = 10080
x 60 = 10080 60 = 168 \therefore \dfrac{x}{60} = \dfrac{10080}{60} = \boxed{168}

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...